The present invention relates to a continuous flow circulatory water heater. More particularly, the present invention relates to a new and improved continuous flow water heater which utilizes a submersible removable pulsating heating mechanism arranged to provide maximum heating efficiency wherein the water is preheated as it rises from the bottom to the top of the caldron, and is heated to its maximum temperature by a pretzel-shaped pulsating pipe prior to exiting the caldron near the top of the caldron.
Continuous flow water heaters of the type disclosed herein are known. For example, reference may be had to German Patent Publication No. DE PS 1,922,650. Further, in particular, the principles in design of the pulsation heater mechanisms utilized herein are known to those skilled in this art. For example, further reference may be had to German Patent Publication Nos. DE PS 1,911,192 and 1,911,193, and to articles published by the inventor herein, namely, in the magazine Betriebs-Okonom, No's. 1 and 2 (1970) regarding Procedures with Gas Operated Resonant or Pulsating Combustion Heater Mechanims, in No. 5 (1970) pp. 96-100, concerning Gas Operated Resonant or Pulsating Burners in Foreign Countries and, in No. 8 (1970) pp. 150-162, on Automatic Starting Process of Resonant or Pulsating Combustion Heating Mechanisms During the Course of their Development, and a special publication entitled Gas Operated Resonant or Pulsating Combustion Heater Mechanisms, published by the Engineering Association of Worttemberg in VD1, presented on the occasion of the conference in Stuttgart on Mar. 5, 1969. The bibliographical references cited in this literature are also worthy of note. In view of this known prior art, a detailed description of the operation of the pulsation heater system will not hereinafter be necessary.
Although continuous flow heater systems are known, the design of a continuous flow hot water system has not yet been optimized. It is an object of the present invention to further develop continuous flow water heaters in such a manner that the individual parts, particularly the intake muffler, the exhaust muffler and the circulation system formed by the combustion chamber and the pulsation pipe, are located in the smallest possible space with the best possible utilization of the space within the volume provided within the caldron. It is a further object of the present invention to provide an arrangement of the operating elements to make the operation of the continuous flow water heater as efficient as possible.
High efficiency of operation is especially important today where there is often a shortage of fuel, and if not a shortage, the cost of fuel is usually rather high. Therefore, efficiency in water heating systems is especially important. Resonant or pulsating combustion heating systems, especially gas fired, are becoming increasingly attractive and may achieve a very high degree of efficiency, possibly up to 99%. Therefore, pulsating combustion systems in accordance with the present invention are particularly appropriate for the solution of heating problems of the future. This is especially the case since it is possible to use explosive materials in the combustion material which could not be burned with an open flame. Thus, the present invention may utilize gases which cannot be burned with an open flame, such as hydrogen or mixtures with a high hydrogen content. There also existed a need for further inventive development in the area of continuous flow water heaters to provide an arrangement wherein the heating elements are arranged in the form of a dip-stick to be immersed in the water so that the material of the caldron was not exposed to a higher temperature than that to which the water will be heated. In this manner, it is even possible to use a synthetic material for the construction of the caldron thereby solving problems such as corrosion and the high cost of conventional prior art caldrons. In addition, the water surrounding the submerged heater unit also serves the function of a sound muffler.
In the case of known mechanisms, an optimal heating of the water circulating or continuously flowing through the container from water intake to water outlet has not, in fact, been achieved. Further, in known devices, the exhaust muffler surrounding the intake muffler in the approximate shape of a ring, caused a certain waste of space in consideration of the diameter of the total mechanism. Further, it should be taken into consideration that in order to achieve the necessary length of the pulsation pipe for a stable pulsation process, an arrangement with relatively great expenditure of cross sectional space must be selected in the mechanism shown there. The latter is necessitated in that there must be resonant conditions at approximately 120 Hz. It could be said that the length of the pulsation pipe is a constant to be considered here, one which nevertheless must be realized in a small space by means of a correspondingly curved shape, while on the other hand, a small curve radius should be avoided wherever possible due to the flow resistance thereby encountered.